1. Match questions 1–4 with answers a–d. Then complete the rule.
(Nối câu hỏi 1–4 với câu trả lời a – d. Sau đó hoàn thành quy tắc.)
1. Was the squirrel eating flowers? a. No, it wasn’t.
2. Were the two men posing? b. Steve’s friend
3. What were the men doing? c. Yes, they were
4. Who was skiing? d. They were using a computer.